The Study Of Aromatic Aldehydes Reacted With The Activated Methyl Of Enaminones

Enaminones are versatile readily obtainable reagents, the structure of them decided that they will become the important intermediate in heterocyclic synthesis. The pyrrole, oxazoles, pyridinones, quinolines, dibenzodiazepines, tetrahydrobenzoxazines and tetronic acids have been prepared from enaminones. Enaminones are also valuable precursors forα-iodol enaminones, 3-amino sugar derivatives, azo-compounds,β-aminoketone, as well as tetrahydropentalenes, tetrahydroindenes, and hexahydroazulenes. In addition, some of these compounds are pharmaceuticals possessing anticonvulsant and analeptic activity, combined with low toxicity.Enaminones have two electron-deficient centres at C1 and C3, while the C2 and amino functions are electron rich. They can thus react with both electrophiles and nucleophiles. Therefore there are quite more research about them, but mainly concentrate on C1, C2, C3 and the nitrogen atom which are active, and had made many valuble azo-compounds. But very little literature concentrated on the activated methyl which closes to the carbonyl of enaminones. So the paper conducts the research to the aldol condensation of aromatic aldehydes with the activated methyl of enaminone.Therefore the paper mainly has following four aspects:1. Enaminones reacted with aromatic aldehydes in the condition of sodium hydro- xide/ethyl alcohol and obtained two products, respectively is the product of single aldehyde reacted with enaminone and the product of double aldehyde reacted with enaminone.2. Enaminones 1 reacted with aromatic aldehydes in the aqueous phase, and used the potassium carbonate or the sodium hydroxide as the catalyst. I found that we can get the different product according to the amount of potassium carbonate and the sodium hydro- xide.3. Enaminones 1 reacted with aromatic aldehydes in the condition of titanium tetra- chloride/methylene chloride. I obtained the single product 6a, but it is not the product we wanted.4. Enaminones 1 reacted with aromatic aldehydes in anhydrous dichloromethane, the titanium tetrachloride and DABCO as catalyst. I got the single product 2 which are we wanted.In brief, we had discovered a way which we can use to make the enaminones reacted with aromatic aldehydes and synthesized 12 products we wanted which can provides the reactant for the next step of synthesizing azo-compounds. The way has the merits of simple experimental technique, the temperate condition and higher rate, so this kind of new condensation product has a better prospect in organic synthesis.